Scents and Sensibility : Special blossoms are more than a treat for the eyes. Their heady fragrances can make the nose gay.

I know the reason my friend Wendy visits me in the spring. She comes to smell my pink jasmine. I find her near the potted vine, pocketing flowers, and she’s always crushed in June when it finishes blooming.

Now in late summer, my night jessamine is blooming, casting its heady aroma into every corner of the yard. Its scent is so intoxicating that it never fails to lure me outside with the stars.

A garden wouldn’t be a garden without fragrance. True, attractive flowers and foliage are the backbone of a landscape, but fragrance perfuming the air makes the garden a magical, tempting haven. Research has shown that our sense of smell is our most evocative. Aromas alter mood. The scent of lavender, for instance, is said to calm nerves.

Scent is often thought of as coming from flowers, but it also originates in leaves, bark, fruit, seeds and roots, says Katie Bloome, a landscape architect and a manager for Monrovia, an Azusa wholesale grower that introduced a fragrant collection of plants that is available throughout Southern California nurseries.

“Fragrance comes from the oils that are in the glands of plants,” Bloome says. “The oils evaporate and the molecules are released into the air, which is what causes scent. There are many different essential oils found in the plant kingdom, and each plant has a mixture of compounds that make up its unique fragrance.”

Essential oils are perceived differently by everyone, which is why a scent may be delightful to one person and repellent to another.

Not all flowers or plants smell. “White and pastel blooms are the most fragrant, and pale pinks are the most potent pastels,” Bloome says. “The darker a flower gets, the less fragrance it will have. Dramatic colored flowers such as orange and crimson may be dramatic in the garden, but they have little or no fragrance.”

Fragrant flowers produce scent to attract pollinators such as bees and discourage pests; non-fragrant flowers use color and shape to do so.

To create a fragrant garden, keep the following in mind:

* Plan a garden that is fragrant year-round. “If you time things right, you can have nice scents in the garden all year,” says Alex Reynolds, a nursery professional at Kitano’s Garden Center in La Palma.

There is a fragrant plant for almost every month, he says. “For instance, star jasmine blooms in spring, while plumeria flowers in summer and fall. There are also ever-blooming plants that smell great most of the year, like many gardenias.”

* Consider the time of day. “Some plants, like night-blooming jessamine, have virtually no scent during daylight,” Bloome says. “During the day you could enjoy the scent of another summer and fall bloomer like lavender; once night falls the jessamine can take over.”

Nicotiana is another night-blooming flower, as well as the aptly named annual moonflower, which smells so nice on late summer and fall nights.

* Avoid combining multiple scents. “You lose out if you mix too many scents at once,” says Jeff Nakasone, general manager of Certified Plant Growers in Norwalk, a wholesale grower and supplier to local independent nurseries. “Some fragrant plants don’t mix well, and others just overpower everything else,” he says.

* Put fragrant plants in high-traffic areas where the odor will be most appreciated, such as in walkways and near windows.

* Encourage aromas to linger by putting fragrant plants in sheltered spaces protected from wind. Small, enclosed gardens tend to trap and hold in fragrance much better than larger ones. Good locations for fragrance include atriums, courtyards and under trellised patio coverings, especially those surrounded by walls or shrubbery.

* Consider more than flowers for aroma. Leaves, fruit, bark, roots, seed pods, buds and stems can also produce a wonderful array of scents. “Many plants have aromatic foliage that will scent the air when a leaf is crushed or brushed,” Bloome says.

Place herbal ground covers, such as thyme and mint, in pathways. Other small plants that release an aroma when brushed include rosemary, lavender and scented geraniums.

* Put fragrant plants near nose level. “No one wants to put their heads to the ground to smell more subtly fragrant plants like alyssum and heliotrope,” Nakasone says. “When possible, put mild-smelling plants in containers at an elevation.” Most shrubs and vines generally grow high enough to easily be appreciated for their fragrance.

* To find a nursery in your area that carries the Monrovia fragrant collection, call (888) Plant It.

* For information from Kitano’s Garden Center telephone (714) 521-2772.